The present invention relates to a method for manufacturing a colored or non-colored metal sheet or coil.
The production of colored metal sheets has grown increasingly in recent years. For example, galvanized steel sheets coated with color paints have already reached half the whole demand for galvanized steel sheets in Japan. Steel sheets coated with color paint immediately on the surface thereof and steel sheets coated with aluminum containing colored paints on the surface of the aluminum are also increasing in production. As to materials to be coated, not only metal materials themselves, but also surface-coated materials of various kinds are painted and put to practical use. With an increase in the production of such colored metal sheets, great progress in technical studies and research has been made with the result that remarkable improvements in various techniques have been achieved. For instance, improvements have been made in the area of double-coatings with color paints, an increase in the coating thickness, an increase in the amount of zinc platings and improvements in the quality of colored coatings. Further, there have also been developed, improvements such as foamed coating, embossing and texturing methods and the like in the colored coating area. However, in the face of qualitative and quantative improvements of colored coatings, as mentioned above, there has been developed a keen imbalance between the technical improvements and methods of elevating the production line speed during the production of such colored coatings.
The present invention is an epochal method of solving the above-mentioned problem and is considered to represent a quite novel and practical method of overcoming this difficulty.